He said: “It was a split second thing because he was doing lengths then when he got to the shallow end it looked like he realised he was having a heart attack and tried to get out, but he fell backwards and that’s when I jumped in.”

Ashley Dower, 18, of Wigginton, was on her break when she heard the call for help.

She added: “I heard the alarm and just legged it towards the pool – I don’t think I have ran as fast in my life.

“I didn’t even think because we are trained every week, so we just got on with it.”

The lifeguards originally thought their efforts had been in vain when they were visited by a police officer who told them the man was struggling shortly after being taken to hospital.

Jonny Woodford, 22, from Haxby, had not long returned home from Manchester University when he witnessed the trouble unfold.

“He started turning blue and was unresponsive,” he added.

“It’s the first time any of us have had to deal with something like it.

“When you look back at it, it’s something you never think will happen, but a relief our training has paid off.”

Manager Lee Brown, 27, was on duty when the man got into difficulty.

He added: “I’ve been here 11 years and nothing like this has happened.

“We were all here the day after and it was quite hard for all of us.

“But he has since come back to see us and brought us some beers and a card with a nice message.

“We were out here about 15 minutes talking, and he said how grateful he was, but we were just doing what we were trained for and we would have done the same for anyone.”